Undersea acoustic sensing systems typically involve a single towed or bottom-mounted (i.e., horizontal) cable array or a single free-floating vertical cable array. In the case of a horizontal array, only bearing is detected while vertical resolution (in terms of angle of depression/elevation) is sacrificed. In the case of a vertical array, angle of depression/elevation is detected at the expense of bearing.
Therefore, a need exists in the state of the art for an undersea acoustic sensing system that can resolve the arrival of acoustic energy in terms of bearing and angle of depression/elevation. Accordingly, it is an object of the present invention to provide an improved underwater sensing system that can simultaneously resolve bearing and angle of depression/elevation of an impinging acoustic signal. Another object of the present invention is to provide an improved underwater acoustic sensing system that accommodates a large number of sensors while minimizing the system processing to minimize the power requirements of the system.